IXOXI: This does not have to be completely true, considering Class D Amplifier (low pass filter at the does not change principle).
WinterSnowfall: Well, yes, there are of course ways to digitally amplify a signal, but the output from the low pass filter is still an analogue waveform that has to get to your speakers, which is the point I was trying to make. There are no
"digital speakers" out there.
This is exactly what I wanted to highlight, from audio file to speaker output everything can be in pure digital form, so we do not have to be afraid about analog audio problem. Low-pass filter at the end basically work as average function which works with signal level much higher than for example noise. Thus in theory yes, at output is signal which can be considered as analog, but it is from obvious reason absolutely irrelevant when we would like to choose beast sound card - it is more like for academic discussion. ;)
But I do not want argue, I only mention it, because original question was for simple answer and it seems to me, that some answers can confuse people who do not have proper background. Personally I agreed with teceem who mentioned, that with analog audio should not be a problem if all is done and set correctly (ground loops, over saturated input, too low signal, etc.).